I'm constantly having air leak into my output line for my two DOS/DDR units. It wasn't leaking for a couple days and my parameters were stable, then it started leaking again. With this system leaking air in the lines it's going to be impossible to get my system stable. I'm going to tear down the system this weekend. Any suggestions on how to get to stop leaking air would be appreciated.
DOS/DDR Bubbles in line
- Thread starter redpine42
- Start date
- Tagged users None
Good if you could add a picture of the pumps set up.
Sincerely Lasse
Sincerely Lasse
Reeferdood
2500 Club Member
I assume you are not using the tubing that came with the unit? The tubing that is designed for the DOS works the best, you get a better seal. I use 2 DOS units with no issues. If you are using the neptune tubing then tighten the nuts a little more and make sure the tube is all the way up in the male portion before tightening the nut.
It looks a little strange. There is IMO not a chans that air can enter into the tubing at the outlet (the pressurized side) but the pictures indicate that. All my experiences says that you should look for the leak on the suction part of the pump.
Sincerely Lasse
Sincerely Lasse
Reeferdood
2500 Club Member
The heads will sometimes leak on both sides if the wrong tubing is used. But you are correct, if it leaks on the outlet side you will have liquid present at the nut.
I’m using the tubing that came with it. I can’t tighten any further with out leverage which I’m sure will break the plastic nut. Also, pushed the tube all the way up. Maybe it slipped since I’m finding the nuts loose over time. Maybe use lock tight on the nuts? Thanks.
Last edited:
Reeferdood
2500 Club Member
I assume you bought the unit new? If so, then it came with the right stuff, their tubing is stiff with neptune stamped on it. I would check the inlet side like lasse pointed out and see if that helps. If not, remove the tubing and re cut the ends and try again.
In case anyone else has this, I contacted Neptune and here is their debugging steps.
"Try removing the Pump head from the DŌS and see if you can adjust the pump tubing, is it pinched or off center?
Ensure the tubing is connected firmly on to the "IN" and "OUT" plastic tips and check to make sure that the compression screws are tight
Check your Tubing. Check the cuts on the tubing are the diameters different? Click here for example. If yours are than contact us.
Try to swap the head units from right to left to see if issue of loosing prime follows the head or stays with the motor?
Remove the pump heads check for cracks or stress fractures in the plastic.
Guide Available here:
https://www.neptunesystems.com/replacing-dos-pump-head/"
"Try removing the Pump head from the DŌS and see if you can adjust the pump tubing, is it pinched or off center?
Ensure the tubing is connected firmly on to the "IN" and "OUT" plastic tips and check to make sure that the compression screws are tight
Check your Tubing. Check the cuts on the tubing are the diameters different? Click here for example. If yours are than contact us.
Try to swap the head units from right to left to see if issue of loosing prime follows the head or stays with the motor?
Remove the pump heads check for cracks or stress fractures in the plastic.
Guide Available here:
https://www.neptunesystems.com/replacing-dos-pump-head/"
Thanks all. I rehooked up my ALK, tightened down everything, emptied the lines and bubbles no new bubbles today. We'll see if that lasts. Need to rebuild my Ca line also today, since that one also has bubbles.
Blakjax
Active Member
I have the same problem. Did this fix the issue?
